calculating diesel cycle efficiency

newe999

1. The problem statement, all variables and given/known data
given:
diesel cycle,
P1V1 P2V2 P3V3 P4V4 - all known
T1 = 20°c
specific heat capacity constant pressure = 1000j/kgk
specific gas constant = 287j/kgk
compression index = 1.4

2. Relevant equations
heres where i am stuck!


3. The attempt at a solution
Hi all, im unsure where to go with this one. im guessing that i need to work out T2.T3.T4, but cant find in any of my notes where any of the γ or R come into play or how to get T2T3T4?. i have already calculated the work done for each stage in a previous part of the question so i have that. Just not too sure on where to go from here to calculate the efficiency of the cycle?
Also sorry if the post isnt written correctly this is my first post on here
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution